Generally, a fluid supply system includes a fluid supply cartridge that may be designed to deliver fluid (e.g., an ink) to a printhead. The fluid supply system may use pressurized air to pump the fluid from the fluid supply cartridge to the printhead. Alternatively, some fluid supply systems may include two fluid supply cartridges of the same fluid type (e.g., same ink color) to enable replacement of a fluid supply cartridge without having to interrupt or pause an operation (e.g., printing).